Where does “air bawah tanah” come from?

air bawah tanah (Indonesian) comes from Indonesian air, from Malay air, from Proto-Malayic air, from Proto-Malayo-Chamic air, from Proto-Malayo-Sumbawan wair, from Proto-Malayo-Polynesian wahiʀ — water.

Ancestry of “air bawah tanah”, step by step

air bawah tanah traces back through 3 separate lines of ancestry.

via Indonesian air

StepLanguageWordMeaning
1Indonesianairwater; a cockfight round which started by...
2Malayairwater; a cockfight round which started by...
3Proto-Malayicairwater
4Proto-Malayo-Chamicairwater
5Proto-Malayo-Sumbawanwairwater
6Proto-Malayo-Polynesianwahiʀwater

via Indonesian tanah

StepLanguageWordMeaning
1Indonesiantanahearth; ground; land
2Malaytanahground; land; earth
3Proto-Malayic*tanahearth; soil
4Proto-Malayo-Polynesian*tanəqearth, soil, land

via Indonesian bawah

StepLanguageWordMeaning
1Indonesianbawahunder; below
2Malaybawahunder, below; under; below
3Proto-Malayic*bawah
Every word from Proto-Malayo-Polynesian wahiʀ